Basically, the cutting and construction method is exactly the same.
In a S&W, however, the kaleidoscope hexagons or octagons (or whatever the final shape) is prominently visible. For instance, if you are using hexagons, the corner triangles (that make it a parallelogram for construction purposes) are from a contrasting fabric, so when finally assembled, it looks like a 6 pointed star with the S&W hex in the center.
In a OBW, there is no contrasting fabric, and Maxine's take on the S&W was to have all the different hexagons blend into each other so you can't immediately identify the shape.
Do a quick Google image search and you should get enough variation to see the differences.